1. Field of the Invention
The present invention relates to an electrophotographic recording apparatus and, more particularly, to a paper feed mechanism for an electrophotographic recording apparatus.
2. Description of the Prior Art
Electrophotographic recording apparatus are used widely as output units of computers, word processors and facsimile equipment. Various types of electrophotographic recording apparatus differing from each other depending on the type of recording medium have been developed. An electrographic recording apparatus disclosed, for example, in J.P.Provisional Pub. (Kokai) No. 60-22143 comprises first and second transfer units capable of being selectively set at a position opposite a toner image formed on the surface of a photoconductor, a first recording paper feed mechanism for feeding a cut sheet of a fixed length into a gap between the photoconductor and the first transfer unit, a first fixing unit for fixing a toner image transferred to the cut recording sheet, a second recording paper feed unit for feeding a continuous recording paper into a gap between the photoconductor and the second transfer unit, and a second fixing unit for fixing a toner image transferred to the continuous recording paper. The recording paper feed mode of the electrophotographic recording apparatus is changed by operating switches provided on a control unit to record images on cut recording sheets or on a continuous recording paper.
Incidentally, the second paper feed mechanism of this known electrographic recording apparatus has two pairs of sprockets disposed on a paper feed path respectively on the opposite sides of a transfer position to feed the continuous recording paper. If the continuous recording paper is reversed, the leading edge of the continuous recording paper is disengaged from the sprockets. Therefore, the continuous recording paper must be set on the sprockets every time the continuous recording paper is reversed, and hence it is undesirable to reverse the continuous recording paper. If the continuous recording paper is not reversed to remove the same from the transfer position, the cut recording sheet is fed over the continuous recording paper in transferring a toner image to the cut recording sheet, which reduces the effective Coulomb force available for transferring the image to thereby reduce toner image transferring effect. Accordingly, separate paper feed paths must be prepared respectively for cut recording sheets and a continuous recording paper, and separate movable transfer units and fixing units must be provided respectively for cut recording sheets and continuous recording paper, which makes the paper feed mechanism complex and increases the size of the electrophotographic recording apparatus. Furthermore, in recording new information, a large blank is formed inevitably after the preceding recording area in which information has previously been recorded to waste the continuous recording paper, because the continuous recording paper cannot be reversed, and the operator must take the trouble to cut the continuous recording paper into cut recording sheets each carrying a group of data.